Method of manufacturing a solid-state imaging device

Abstract

A method of manufacturing a solid-state imaging device, wherein the solid-state imaging device comprising: a semiconductor substrate; a plurality of photodiodes that are formed on a surface of the semiconductor substrate so as to be arranged in an array form; and a light shielding film, provided on or above the surface of the semiconductor substrate, that has a plurality of openings in correspondence with respective ones of the photodiodes, the method comprising: laminating, on the surface of the semiconductor substrate, lamination layers including the light shielding film; opening through holes in the lamination layers, respectively, at positions corresponding to the photodiodes to form the openings in the light shielding film; forming a low refractive index material layer with a predetermined thickness isotropically on a side wall surface of each of the through holes; and filling a remaining hole portion of each of the through holes with a high refractive index material to form an optical waveguide for guiding incident light to each of the photodiodes.

1. A method of manufacturing a solid-state imaging device,
 wherein the solid-state imaging device comprising: 
 a semiconductor substrate; 
 a plurality of photodiodes that are formed on a surface of the semiconductor substrate so as to be arranged in an array form; and 
 a light shielding film, provided on or above the surface of the semiconductor substrate, that has a plurality of openings in correspondence with respective ones of the photodiodes, 
 the method comprising: 
 laminating, on the surface of the semiconductor substrate, lamination layers including the light shielding film; 
 opening through holes in the lamination layers, respectively, at positions corresponding to the photodiodes to form the openings in the light shielding film; 
 forming a low refractive index material layer with a predetermined thickness isotropically on a side wall surface of each of the through holes; and 
 filling a remaining hole portion of each of the through holes with a high refractive index material to form an optical waveguide for guiding incident light to each of the photodiodes. 
 
     
     
       2. The method of manufacturing a solid-state imaging device according to  claim 1 ,
 forming, in advance, a reflection preventing film comprising a high refractive index material on each of portions of a gate insulating layer on the semiconductor substrate which corresponds to a receiving surface of each of the photodiodes, 
 wherein the reflection preventing film is used as an etching stopper when the through hole is opened. 
 
     
     
       3. The method of manufacturing a solid-state imaging device according to  claim 1 ,
 wherein the low refractive index material layer is formed with plasma CVD. 
 
     
     
       4. The method of manufacturing a solid-state imaging device according to  claim 1 ,
 wherein the low refractive index material layer has a thickness of 0.1 μm or more. 
 
     
     
       5. The method of manufacturing a solid-state imaging device according to  claim 1 ,
 wherein the low refractive index material layer comprises SiO 2 . 
 
     
     
       6. The method of manufacturing a solid-state imaging device according to  claim 1 ,
 wherein the high refractive index material comprises SiN. 
 
     
     
       7. The method of manufacturing a solid-state imaging device according to  claim 1 , further comprising:
 forming an upwardly convex inner lens on or above the high refractive index material forming the optical waveguide; 
 forming a flattening layer on the upwardly convex inner lens; 
 forming a color filter layer on or above the flattening layer; and 
 forming a top microlens on or above the color filter layer.